Bluish-violet disazo dye.



nrrnn STATES PATENT OFFICE.

; ARTHUR ZART, OF VOHWINKEL, NEAR ELBERFELD,TGER1VIANY, ASSIGNOR- 'TO FAR- BENFABRIKEN VORM. FRIEDR. BAYER & 00., OF ELBERFELD, GERMANY. A COR- PORATION 0F GERMANY.

BLUrsn-vIoLErnIsAzo DYE.

No Drawing.

Specification of Letters Patent.

Patented Dec. 26, 1911.

Application filed September 1, 1911. Serial No. 647,254.

To all whom 'it may concern:

SOgH S0 with 2 molecules of the 5.5 -dioxy-2.2'-dinaphthylamin-7-7-disu1fonic acid (See British Letters Patent No. 24296/99) In order to illustrate the new process more fully the following example is given, the parts being by weight 2-344 parts of benzidin-ortho-ortho -disulfonic acid are tetrazotized with 138 parts of sodium nitrite and hydrochloric acid and the tetrazo compound thus produced is combined with a solution of'922 parts of 5.5 -dioxy-2.2dinaphthylamin-7 .7 '-disulfonic acid containin an excess of sodium bicarbonate (Natl-I60 The product of the reaction is heated to about 60 C. and the new dye is precipitated by the addition of common salt,

filtered off and dried. It is a dark powder soluble in water with a violet coloration,

and soluble in concentrated sulfuric acid with a blue coloration, yielding upon reduction with stannous chlorid and hydrochloric acid benzidin-ortho-ortho,-dis.ulfonic acid and 5.5-dioxy6-amino-2.2-dinaphtHyla nin-Z'Z'-disulfonic acid; and dyeing cotton bluish-violet shades fast to ironmg.

I claim The herein described disazo dye having I most probably the formula:

which is after being dried and pulverized in the shape of its sodium salt a dark powder soluble in water with a violet coloration and being soluble in concentrated sulfuric acid with a blue coloration; yielding upon reduction with stannous chlor' and hydrochloric acid 5.5 -di0xy-6-amino- .2'-dinaphthyla'min7 .7 -disulfonic acid and benzidinortlio-oi'tho -disulfomcv acid; and dyeing cotton bluish-violet shades fast to ironing, substantially 'as described.

In testimony whereof I have hereunto set my hand in the presence of two subscribing. Witnesses.

ARTHUR ZART. [1 s.] Witnesses: CHAS. J. WRIGHT,

L. NUFER. 

